collective
hallucination

Where belief in miracles exists, evidence will
always be forthcoming to confirm its existence. In the case of moving statues and
paintings, the belief produces the hallucination and the hallucination confirms the
belief. --D.H. Rawcliffe

A collective hallucination is a sensory hallucination induced by the power of
suggestion to a group of people. It generally occurs in heightened emotional situations, especially among the
religiously devoted. The expectancy and hope of bearing witness to a miracle, combined
with long hours of staring at an object or place, makes certain religious persons
susceptible to seeing such things as weeping statues, moving icons and holy portraits, or
the Virgin Mary in the clouds.

Those witnessing a "miracle" agree in their hallucinatory accounts because
they have the same preconceptions and expectations. Furthermore, dissimilar accounts
converge towards harmony as time passes and the accounts get retold. Those who see nothing
extraordinary and admit it are dismissed as not having faith. Some, no doubt, see nothing
but "rather than admit they failed...would imitate the lead given by those who did,
and subsequently believe that they had in fact observed what they had originally only
pretended to observe....(Rawcliffe, 114).

Not all collective hallucinations are religious, of course. In 1897, Edmund Parish
reported of shipmates who had shared a ghostly vision of their cook who had died a few
days earlier. The sailors not only saw the ghost, but distinctly saw him walking on the
water with his familiar and recognizable limp. Their ghost turned out to be a "piece
of wreck, rocked up and down by the waves" (Parish, 311; cited in Rawcliffe, 115).

Thousands wait for Knock apparition Joe Coleman, a Dubliner
who fancies himself clairvoyant, predicted the Virgin Mary
would appear at the old parish church in Knock. A crowd
estimated at more than 5,000 showed up, some claiming they could
see the sun shimmering, changing color, and dancing in the sky,
which they took for a sign from the heavens.